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Climate Change and Health

Many health care professionals are already dealing with the effects of climate change. In this Q&A, the World Health Organization’s first-ever Special Envoy for Climate Change and Health, Vanessa Kerry, MD, MSc, joins JAMA Medical News Director Jennifer Abbasi to discuss how a changing climate and extreme weather events are impacting human health, what clinicians should expect in the years ahead, and how they can help protect patients—and the planet.

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[This transcript is auto-generated and unedited.]

[Jennifer Abbasi] Hello and welcome to this Q&A. I'm Jennifer Abbasi for JAMA Medical News. Today's Q&A is devoted to climate change and health, a topic that JAMA will increasingly be focusing on in research articles, opinion pieces, news stories, and lots of other content. Here are a couple sobering stats. The National Oceanic and Atmospheric Administration reports that the 10 warmest years on record have all occurred since 2010. This year's June and July were the hottest of these months on record for both global land and ocean temperatures. In fact, July was likely the hottest of any month since global record keeping started in 1850. The reality is that many healthcare professionals are already dealing with the impact of climate change, whether personally or in their clinical practice or both. People around the world are feeling the effects of heat waves, droughts, wildfires, storms, and flooding. According to a new study published in July, it's now estimated that more than 60,000 people died from heat-related causes in Europe last year during its hottest season on record. Joining me today to talk about these challenges is a physician and global health expert who has recently been appointed the World Health Organization's first ever director general special envoy for Climate Change and Health. Dr. Vanessa Kerry is a critical care physician at Massachusetts General Hospital where she is also the associate director of the Center for Global Health. She directs the Global Public Policy and Social Change Program at Harvard Medical School. She's also the co-founder and CEO of Seed Global Health, a nonprofit organization that helps to train and advocate for the health workforce in Sub-Saharan Africa, a region that is deeply affected by climate change. Dr. Kerry, thank you for being here.

[Dr. Vanessa Kerry] Thank you. I'm delighted to join you, especially to talk about this incredibly critical topic.

[Jennifer Abbasi] I want to get to the health effects of climate change that clinicians can expect to deal with in the coming years and how they can be prepared. But first, let's talk about why the WHO decided to create this new position focused on climate change and health. Why was now the right time?

[Dr. Vanessa Kerry] Well, I think the WHO has really been working incredibly hard in this space of climate change and health and have an entire department dedicated to the environment, climate change and health, which is an unbelievable team pulling together the data, helping us to understand exactly how our communities and our countries and our globe are being impacted by what is fundamentally a health crisis. The climate crisis is a health crisis. 7 million people a year are dying from air pollution already. This is a year that's more than died in the entire COVID pandemic throughout the three years. So we are facing very real challenges from health that have made this ultimately our next pandemic, and one that is fundamentally challenging our human survival and our future. And so for the WHO, this is a critical area that we have to be engaged in and creating very rapid solutions to respond today and to adapt to, to build the resilience of our health systems and to help make sure that we're mitigating the health sector's impact on our contributions to the climate change space.

[Jennifer Abbasi] So what are some of the various ways that the health of populations around the world is already being affected by a changing climate?

[Dr. Vanessa Kerry] So climate change, as greenhouse gases increase and they are increasing every year, it creates global warming. And what that does is creates masses of extreme weather. It creates changes in flooding, it creates droughts, it creates changes in our air quality. It warms our oceans, it changes our food sourcing. And what we're seeing is a rise in disease across pretty much every disease grouping you could think of. It creates an increase in vector-borne and communicable diseases. It creates an increase in non-communicable diseases, cancer, cardiovascular disease, kidney disease, pulmonary diseases. It creates an increase in maternal health issues and maternal mortality with increases in stillbirths and preterm births. And we're seeing an increase in mental health issues as well as the trauma, of course, from things that happen in extreme weather events, drownings and things like that. If you take the example of extreme heat here in the United States, Phoenix spent over 30 days over three digits. Extreme heat is costing the United States a hundred billion in productivity a year. That's expected to double by 2030. So this is also affecting our livelihoods and our ability to have access to resources and to care for our families. So the health impacts are both direct and indirect, and they're creating a really real and vicious cycle that is going to impact people's access to thrive and will drive a lot of people into poverty. And so then you're getting into the social determinants of health that impact our wellbeing. And climate change has a huge impact on those too. So it's a very real and profound problem that is, again, truly threatening our daily existence.

[Jennifer Abbasi] What types of climate associated health issues can clinicians expect to see more of in the coming years?

[Dr. Vanessa Kerry] Well, I think clinicians are going to see it all. I mean, I think there's a rise in mental health and stress and anxiety that's coming from the climate changes and the uncertainties that are coming with it. Without question, we're seeing an increase in vector-borne diseases. Dengue now affects over half the world's population. It's expected to rise to 60%. If you just look at the United States here alone, we've had the first cases of transmission of malaria in Texas and in Florida that we've seen in over 20 years. And we know that tick-borne diseases, the CDC just came out telling us that there's been a drastic rise in the alpha-gal or the vector-borne diseases coming from the lone star tick that we're seeing that habitat change with global warming. But we're also seeing noncommunicable disease. There's rises in pulmonary disease from air quality. We're seeing increases in kidney disease from extreme heat and dehydration as an example. We are seeing increases in cardiovascular disease and the effects that are coming from that. And cancer. Believe it or not, the cancer mechanisms come sometimes even just from evaporations of lakes and the volatile gases and elements that are getting exposed that are making us sick. So there's myriad different ways that we're getting directly impacted. And clinicians healthcare workers are going to see this in their practices with more and more frequency, but they're also going to be seeing and having to contend with some of the social determinants of health that we have to think about.

[Jennifer Abbasi] Globally, heat waves have becoming more frequent, longer and more intense. In the US, parts of the Southwest had record-breaking heat in July. As you mentioned, Phoenix, Arizona had 31 days in a row of temperatures above 110 degrees Fahrenheit. Older adults and people who work outdoors or who are unsheltered are some of the populations that are particularly vulnerable during heat waves. How should the world be preparing for more extreme temperatures?

[Dr. Vanessa Kerry] The way we should be preparing is by drastically reducing the greenhouse gases that we're putting into the atmosphere. The reality is that greenhouse gases are going up every year, and that's going to contribute to the global warming picture. We're on track right now to hit 2.4 to 2.6 degrees Celsius over the next immediate period, not even close to the Paris Agreements goal to stay at 1.5. And health experts have already said we are in unchartered territory. So some of this is going to be also about how we are sort of protecting our communities and making resources available. Because without access to air conditioning or cooling systems or safe water or mechanisms to escape the heat, it's going to be very difficult to manage. And it's hard. Individuals can try to do what they can, but this is going to be a systemic issue where parts of where we live are going to become uninhabitable and people are going to end up moving. And so, I'd love to say that there's a clear pathway for clinicians to take, but it's impossible to walk away from the macro here, which is that we are facing such drastic changes on a very system-wide scale that some of this is going to be about we have to get to the root cause of the problem in this as well. As much as we want to be reactive as clinicians, we have to take it upon ourselves as caregivers also to start to highlight exactly how damaging this is for our patients, our populations for this country, for the world, and become real advocates for what's happening. I think if you look globally, for example, this is very real too because those countries that are least contributing to climate change are those that are also the most vulnerable and have the least amount of resources to be able to react to climate change. And what that's going to look like is about 1.2 billion people by 2050 who are going to be displaced and are going to be engaging in migration.

[Jennifer Abbasi] To what extent do you think health systems are ready for influxes of patients who are dealing with extreme heat?

[Dr. Vanessa Kerry] So health systems are stressed because they don't have all the resources they need to manage the disease we have today. They also don't necessarily... So we're not remotely ready for the disease that we're going to see coming down the pipeline, whether it's extreme heat or the noncommunicable disease and the air pollution, or if it is the vector-borne diseases that we're seeing. Pakistan's a great example. After the floods and that extreme weather event, the malaria cases quadrupled in the country. So it went to about 1.6 million cases, including in provinces where it had been eradicated. That's a huge new stress on a health system that already has a number of challenges. We're now looking at an increased flux of disease at a rapid rate from climate change that in its own way is going to be a COVID pandemic many times over year in and year out, whether it's wildfires in Hawaii that we're seeing right now, the smoke that was coming down from Canada, the extreme heat that we've seen, the flooding and devastation, the new vector-borne diseases that are coming, all of this is going to challenge our health systems. And we have an opportunity though. I'm actually, I'm a total optimist, believe it or not. I'm sitting here giving a doom and gloom sort of picture, but we can change the course of how we react and we can change the course of what we're dealing with. It's a choice. We can choose here now to begin a path of transition to less greenhouse gases. We focus on prevention, make people healthier, we contribute less greenhouse gas. Any disease puts in much more greenhouse gases as they pursue care and use more services. So we're facing a choice and an opportunity to really reorient how we're doing health and focusing on prevention. And we'll not only be able to manage climate, but we're going to be able to manage the diseases we're seeing today. People will live longer, they will be healthier and happier, and we are ultimately going to be saving ourselves.

[Jennifer Abbasi] That's so interesting. I never really thought about the contribution of disease itself to climate change, so that's really interesting. You mentioned wildfires. Dr. Kerry, here in Chicago where JAMA is headquartered, we had an unusually hazy June. We're one of the regions that have been affected by smoke from Canada's most severe wildfire season on record. So what happens to air quality when wildfires increase?

[Dr. Vanessa Kerry] Well, when wildfires increase, you see an increase in the particulate matter that enters the air into small... Basically the smoke inhalation and all these pieces that can create changes in your lungs can make it hard to breathe. If you have asthma or reactive airway diseases, they can get triggered and you can have problems there. Over the long-term, these exposures can also obviously lead to malignancies or to other long-term lung disease. For those folks with cardiovascular disease, it can increase stress and in cardiovascular disease. The inhalation effects are full of compounds that your body is not designed to want to absorb and to manage that can go on to lead to considerable disease either in the short term or in the long term. And as we're seeing accelerated events like this and they're impacting huge communities, the visual alone of seeing New York City under an orange haze was quite profound. That's 22 million people that were deeply exposed to a huge amount of environmental insult to their bodies. Again, it gets a little bit also manifest by where you're already living and what your resources are to manage it and your ability to access masks or to stay indoors. And for those people whose jobs are outdoors or they have to continue to work in that environment, they're put at higher risk. And those are often the folks that are already more vulnerable. So we're going to see pretty profound... As these wildfires accelerate, we're seeing profound impacts. But look at Hawaii, people were running into the ocean and had to be rescued by the Coast Guard on Maui because of the fires and the physical danger that was happening there. And then in addition to the physical danger of what happens to us, you lose your houses, you lose your livelihoods, you lose your jobs as businesses burn down. And that again, has a long tail of impact about your ability to access health as you suddenly have to make choices between food or seeking health services and copays, or if you are stressed from the mental health burden of suddenly losing your family or your livelihoods and having to protect your family. These all have long tails and everything is deeply interconnected. And the more severe and the more frequent these events are happening, the more we're at risk of all of these things. And smoke, by the way, isn't just a cross border between two nations that touch. We can see smoke transmit across huge areas of this earth in a way that we can be subject to what's happening in somewhere very far away.

[Jennifer Abbasi] Yeah, I think the Canadian wildfire smoke ended up reaching Europe. [Dr. Vanessa Kerry] Yep.

[Jennifer Abbasi] You mentioned flooding. Extreme flooding has been reported this year in places including China, India, Japan, and the US' eastern seaboard. And last year, monsoon rainfalls in Pakistan caused unprecedented flooding that affected 33 million people. What are your concerns when you see these reports?

[Dr. Vanessa Kerry] Well, I mean there's a number of concerns. One is just the alarming rise rate of these vents is one huge concern. But obviously there's immense physical harm that comes from extreme flooding. One is drowning, direct drowning and death that comes from the increased water. Second is a huge amount of vector-borne diseases. You see rises in malaria, rises in dengue and mosquito-borne illnesses. But you also see cholera. You see diarrhea diseases. You see disruptions in water and sanitation. We have to recognize that climate change is here. It is killing us, and it is a health crisis.

[Jennifer Abbasi] JAMA Medical News recently covered research showing that weather-related power outages pose an increasing threat to people who rely on electronic medical devices. This is something I think a lot of people may not think about when they think about climate change, but it's vitally important for a lot of patients. As more communities experience interruptions in power, what role will physicians and healthcare systems have in ensuring ongoing care for all patients?

[Dr. Vanessa Kerry] Well, this is an incredibly complex question because some of this depends on exactly what types of medical devices we're talking about. And we are going to see a loss of life from that or worsening of disease patterns as it comes about. Or we're going to be investing in gas scheduling generators that are contributing and we're going to enter this vicious cycle as well. So I think health systems and clinicians need to be thinking about what this means for their patients and starting to screen the same way we sort of screen for abuse or we screen for whether you have access to food or are safe in your homes and things like that. We're going to have to screen for our climate vulnerability as well and understand what the mitigation plan is for our patients to be able to protect themselves and prepare for this because extreme weather events are happening with more frequency. So this is a new engagement that I think we're going to have to do as clinicians when we think about the determinants of our patient's health and the environments that they live in. Part of the safety is going to be their climate safety.

[Jennifer Abbasi] Let's move on to solutions. You mentioned that you're an optimist, so let's talk about your goals. What are some of the things you hope to accomplish in your new role at the WHO?

[Dr. Vanessa Kerry] So the goal of this position is sort of threefold. One, it's to really advocate and to change the thinking and understanding among policymakers, leaders, and across sectors, right? So political, private sector, labor ministers and finance ministers to understand the deep connection between health, climate and health, and all these other sectors as they happen. And so some of that's going to be working with the UAE and the COP28, which is the big climate conference that happens every year, and this one is in the UAE. So we're working with the presidency of this climate conference, which is dedicated at the first ever day of health on very clear deliverables that we can create from that day that change the political value and calculus of the climate change and health nexus and change how policymakers engage this space and to make better decisions to protect the health and wellbeing of their population. The second big thing is going to be to really change the financing around it, because right now, only about 0.5% of climate financing goes to the health space. And not nearly enough of that in absolute dollars is going to the climate and health space because the investments we need to make is to close the gap of the 10 million healthcare workers that we see around the world to create strong health systems that they can work in with the tools that they need with green electricity, with all the ability to respond to the various types of diseases that we've outlined that are going to come down the pipeline from climate change and be able to meet that demand. Because if you have a healthy population and you can care for those diseases, they can go to work, they can be taxed and create contributions to the GDP, you can actually see productivity. You see more stable homes and communities, more stable nations. You see the gender equity gaps close and women get jobs in the health sector and are paid. They then contribute more to the social sectors in these countries or invest more in health and education in turn. And so there's huge positive benefits that can come if we start to transform the investments we make. And I'd like to help advocate with the WHO and with others to change that thinking and to see a change in money for our overall resilience and wellbeing and to make that shift with data-driven, but also advocacy in politics, but to change the fundamental financing of it and to increase the amount that's available to the climate and health nexus. And the third is to support the director general of the WHO and the WHO and how they're engaging this strategically to look for the opportunities to be able to help make these linkages across sectors. For example, the multilateral development bank. So the World Bank and the Islamic Development Bank and the African Development Bank and others came together to announce a $1.5 billion fund to basically drive investments in primary healthcare, which again will manage 80 to 90% of the disease burdens we see in the world. But that also is our climate resilience. And I guess I would just say I come at this as a clinician who has seen firsthand what some of these impacts can be on patients. And I come at this as a mother. I have two small kids who are so aware of climate change and so frustrated even at their young ages about the fact that people don't seem to be making the right choices.

[Jennifer Abbasi] Let's talk about training the global medical workforce. Clearly, medical education will need to incorporate the realities of climate change. What recommendations do you have for educating students and practicing clinicians?

[Dr. Vanessa Kerry] I think that as clinicians, we are lifelong learners. So there's an opportunity to learn no matter where you are in your career. I think all medical schools and nursing schools and all health professional schools need to have programs dedicated to climate change, both to educate about the increasing risks to human health from climate change and all the ways that climate change can impact human health to understand the health sector's impact on climate change. So again, 5% of greenhouse gases come from the health sector. That's actually more than the airline sector, which I think people don't realize. So we have a real role in our own practices as administrators and in hospitals to think about how we can reduce our own impact in this, and to make sure we're asking questions as clinicians to challenge the system about how we're playing a better role. I think that there's also ways that we have to learn about how we're going to protect, again, that kind of climate vulnerability of our patients and think about where the social determinants of health are, and to start to route ourselves more on a prevention focus because we're not going to be able to keep up with the costs if we stay really heavy on the treatment side. We're going to have to really think about what it means to prevent disease. And you can't do that without engaging in this climate and health nexus in this day and age. And so I think that there's a lot of opportunity to increase education and awareness about that. And then there's the kind of fun side, which is the co-benefits, right? You can help educate your patients that if they walk or they bike somewhere, not only are they reducing their greenhouse contribution to the world, but they're getting healthier as they do it. And so, I think some of this is about reframing values. But we need to be doing this at every level, at the student training level, but we should be doing at the CME level and at the health professional level, hospital levels, whether it's private or academic. And I think the industry should be doing it too, right? A lot of clinicians are now working in industry and not necessarily in the clinical setting. And I think learning about it and not setting [inaudible] can be critically important because of that 5%, again, that is contributing to the greenhouse gases from the health sector, 50% of it is from the pharmaceutical supply chain pathway and 45% of it is from the patient care pathway. So all of us are responsible for thinking about what that contribution, that 95% is that we can help reduce.

[Jennifer Abbasi] I want to close with something you just touched on, which is what role physicians have to play and clinicians in general. Beyond caring for patients who are affected by climate change, what else can healthcare professionals do?

[Dr. Vanessa Kerry] I mean, I think healthcare professionals have a profound role in this, where we live on the front lines of seeing the impacts of what are happening every day. We have powerful stories and narratives, and there's a growing understanding from advocates and civil leaders and stuff that stories are really powerful sources of creating change. We have the ability to take our daily experience and build powerful narratives and to bring evidence and data forth to help change things and to know that we as scientists, and we as clinicians can be really trusted voices in this. But we need to get proactive about being advocates and we need to learn the tools of advocacy and we need to engage not just our patients and our leadership within our hospitals or within our health communities, but I think we need to start helping to really raise this at high political levels too and to think about what that can look like and to engage. Because I keep saying it, that we are really facing a profound health crisis from what we're seeing in climate change. And the work is only going to get harder if we can't find a way to tackle this here and now.

[Jennifer Abbasi] Well, thank you so much, Dr. Kerry. We really appreciate your time. And best of luck with your important work.

[Dr. Vanessa Kerry] Thank you so much.


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